Below is an SC4 file that I created for an Orion to get it to go into the ham band. You'll have to know the frequency table for the radio that want to use, but this is the basic file. If you look closely, you'll see the pattern. "1A39DE00" in Hex is 440000000 in Dec. The last two digits in the first string are "1A," the second is "39," etc. It is repeated three times. One for the TX, one for the RX and one for the display in the software. You may be able to find a ready-made SC4 or SC5 file or you could try this file. Just copy the text below and save it as "440_10.SC4" to somewhere on your computer. You'll have to tell the software to enable SC4 files and then point the software to that file. It'll either work or it won't. Just try a simple personality and put in 455.000 in the RX and TX and program. If it works, you should be able to read the radio and it will show 445.000 in both areas. If it doesn't work, you'll have to find the frequency tables for the P7100.
What you're doing is moving the base, or bottom frequency, of the radio 10 MHz lower. So instead of 450, the new base will be 440.
Word of caution though, once programmed, you will not be able to read and then write back to the radio. You'll get an out-of-band warning. You'll have to use the original pers and modify it if you want to make changes. The other caveat is that every frequency has to be entered 10 MHz higher that the actual frequency, so if you have any frequencies within 10 MHz of the top end of the radio (usually 510-520 MHz), then you will lose those. Good luck!
Code:
// Orion 450-520 MHz to 440-510 MHz for 70 centimeter use.
// Program 455.000 MHz to get 445.000 MHz
// MOVES BASE FREQ TO 440 MHZ ((WAS 450 MHZ))
FREQTBL /f /b0 /=1A
FREQTBL /f /b1 /=39
FREQTBL /f /b2 /=DE
FREQTBL /f /b3 /=00
FREQTBL /f /b4 /=1A
FREQTBL /f /b5 /=39
FREQTBL /f /b6 /=DE
FREQTBL /f /b7 /=00
FREQTBL /f /b8 /=1A
FREQTBL /f /b9 /=39
FREQTBL /f /bA /=DE
FREQTBL /f /bB /=00